When I looked into this, EA Daily also had the same claim, seen here:
https://eadaily.com/en/news/2026/03/23/yuri-shvytkin-deputy-chairman-of-the-state-duma-defense-committee-died-suddenly. Then when I dug deeper into this article it said that this statement was made on the website of the State Duma, a government website where if this was true it would definitely be reliable. However I scoured that website and couldn't find this statement,
http://duma.gov.ru/en/news/chairman/. Furthermore, EA Daily posted this article in March, and on the State Duma website there was an overall lack of announcements made in March. There is also this X post
https://x.com/sotanews/status/2036222432638345438 that claims the same information from the same source. The X post was from another news organization. Given that the topic at hand is a death announcement there aren't really any biases that could be at play from these various news sources.
Given that multiple sources claim this to be true I believe that it likely is, since they are citing a government source. However since I can't find the exact statement they are referencing, I can't guarantee that it is true.